Winding – tensioning – or guiding – Reeling device – With spring motor
Reexamination Certificate
1999-08-03
2001-03-06
Jillions, John M. (Department: 3653)
Winding, tensioning, or guiding
Reeling device
With spring motor
Reexamination Certificate
active
06196487
ABSTRACT:
FIELD OF THE INVENTION
The invention relates generally to seat belt retractors and more specifically to a coupling device for transmitting torque to a spool for driving the spool.
DISCUSSION OF THE PRIOR ART
A coupling device of this type is known from DE 29506208 U1. In the known coupling device, a torque is transmitted from a driving member, which is set in rotation by a tightening drive, to a driven member, which is connected to a belt reel of a seat belt retractor, for driving the belt reel in the belt winding direction. The seat belt is thus tightened on the vehicle occupant's body. The coupling element located on the driving member in the form of a pivotal coupling pawl is kept in the disengaged state by spring force. On rotation of the driving member, the coupling element is brought into interlocking engagement with the driven member such that the torque is transmitted from the driving member via the driven member to the belt reel of the seat belt retractor.
It is an object of the invention to provide a coupling device in which the coupling element is reliably brought into the engaged position in a short time using simple aids.
According to the present invention, the inert mass of the coupling element mounted on the driving member is utilized to bring the coupling element reliably into the engaged position in which the coupling element is interlocked with the driven member using simple guide means which can be designed in the form of mutually engaging pins and guide slots and/or guide surfaces.
The coupling element is preferably moved against the spring force from the rest position into a guided position. This movement takes place as a result of the inertial force resulting from the inertia mass and acting on the coupling element. In the guided position, or in the guided state, the coupling element moves radially inwards with respect to the axis of rotation of the driven driving member until the coupling element reaches the engaged position. In the process, the coupling element can be pivoted, in particular with the region comprising an engagement member interlocking with the driven member, round a pivot axis outside the axis of rotation of the driving member, whereby the pivot axis can rotate with the driving member. In this embodiment, the engagement movement is formed by the pivoting movement which the engagement member of the pivot element performs round the pivot axis and the rotational movement which the pivot axis performs round the axis of rotation of the driving member.
The driven member can be rotationally engaged with the belt reel, and the belt reel and the driven member can be arranged coaxially. The axis of rotation of the driving member can also lie coaxially with the common axis of the driven member and the belt reel.
A path of travel preferably located on the driving member can be provided between the rest position and the guided position or the guided state of the coupling element. The path of travel can be designed in the form of a slot in which a bearing pin of the coupling element engages. The path of travel extends substantially tangentially to a circle, or over a circle, round the axis of rotation of the driving member. At the beginning of the driven rotation of the driving member, the coupling element is moved along this path of travel and brought from the rest position into the guided position as a result of its inertia mass. In the guided position the coupling element comes, with a guide means provided thereon, for example in the form of a control pin, into contact with a guide means provided on the driving member, in particular in the form of a control face or control edge which can be a lateral limit of a slot in the driving member. The desired engagement movement of the coupling element is brought about by the positioning of the bearing pin in the first slot and the guidance of the control pin along the control face or edge which extends substantially over a circle round the axis of the bearing journal. In the guided state, the coupling element which is subjected to the influence of its inert mass is supported and guided at two positions, namely at its pivot axis and by the other guide means on the driving member.
In the engaged position, the coupling element is supported on the driving member, preferably on at least two support points, such that reliable transmission of the torque to the driven member is ensured. The two support points can be substantially diametrically opposed with respect to the axis of rotation. There is preferably an interlocking fit between the coupling element and the driving member along relatively large contact faces at the support points. Apart from the reliable transmission of torque, this ensures that the high-pressure forces occurring do not deform the components forming the support points.
The coupling element is preferably designed as a two-armed lever of which the axis is formed by the pivot axis that comes into effect in the guided state of the coupling element. One support point is located on one lever arm and the other of the two support points on the other lever arm. The spring force that acts between the driving member and the coupling element and keeps the coupling element in the rest position is formed by a spring preferably designed as a tension spring. One end of the spring acts on the driving member and the other end of the spring on a lever arm, in particular on the end of the lever arm of the coupling element. The engagement member interlocking with the driven member in the engaged state is located on the other lever arm of the coupling element. The guide means are preferably located on the lever arm end or in the vicinity thereof.
When the coupling is engaged, the driving force of a tightener drive, which can be pyrotechnical, mechanical or the like in design, is transmitted from the driving member in order to tighten a seat belt wound onto the belt reel. On completion of the tightening process, the restoring force of a motive spring which is provided in the conventional manner acts in the belt winding direction on the belt reel when the seat belt webbing is relaxed. The interlocking elements, in particular teeth, which are provided on the driven member and on the engagement member of the coupling element and are mutually engaged in the engaged state, are arranged such that they are released from one another by this torque. The spring which biases the coupling element into the rest position, also acts on the coupling element and moves it, after release of the interlocking fit on the respective support faces, along the guide path into the rest position. After tightening of the seat belt, therefore, the seat belt retractor is available again as an automatic self-winding device.
REFERENCES:
patent: 4618108 (1986-10-01), Butenop et al.
patent: 4750686 (1988-06-01), Fohl
patent: 5730384 (1998-03-01), Fohl
patent: 5749536 (1998-05-01), Specht et al.
patent: 6010589 (2000-08-01), Schmidt et al.
patent: 6105893 (1999-07-01), Fohl
patent: 295 06 208 U (1995-07-01), None
Knych Andreas
Specht Martin
Breed Automotive Technology Inc.
Drayer Lonnie
Jillions John M.
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